Objective To determine the patient and clinical variables associated with administration of any analgesia, nurse-initiated analgesia (NIA, prescribed and administered by a nurse) and early analgesia (within 30 min of presentation). Methods We undertook a retrospective cohort study of patients who presented to a metropolitan ED in Melbourne, Australia, during July and August, 2013. The ED has an established NIA programme. Patients were included if they were aged 18 years or more and presented with a painful complaint. The study sample was randomly selected from a list of all eligible patients. Data were extracted electronically from the ED records and by explicit extraction from the medical record. Logistic regression models were constructed to assess associations with the three binary study end points. Results 1289 patients were enrolled. Patients were less likely to receive any analgesia if they presented 08:00-15:59 hours (OR 0.67, 95% CI 0.46 to 0.98) or 16:00-24:00 hours (OR 0.55, 95% CI 0.37 to 0.80) were triage category 5 (OR 0.20, 95% CI 0.08 to 0.49) or required an interpreter (OR 0.34, 95% CI 0.14 to 0.86). Patients were less likely to receive NIA or early analgesia if they were aged 56 years or more (OR 0.70 and 0.63; OR 0.57 and 0.21, respectively) or if they had received ambulance analgesia (OR 0.59, 95% CI 0.36 to 0.95; OR 0.38, 95% CI 0.20 to 0.74, respectively). Conclusions Patients who present during the daytime, have a triage category of 5 or require an interpreter are less likely to receive analgesia. Older patients and those who received ambulance analgesia are less likely to receive NIA or early analgesia.